1. Field of the Invention
The present invention relates to a thermally stable, impact and electrostatic discharge resistant explosive detonator. More specifically, the present invention relates to an explosive detonator including an r.function. attenuator, a semiconductor bridge, a spark gap, cyclotetramethylene tetranitramine or other explosive and titanium subhydride potassium perchlorate or 2-(5-cyanotetrazolato)pentaaminecobalt (III) perchlorate and, in some instances, a bleeder resistor and a capacitor.
2. Description of the Prior Art
It is well known in the art to initiate secondary explosive compositions by means of primary explosives. This method however, involves the use of materials which are subject to accidental initiation by extraneous sources such as, for example, heat impact, friction, electrostatic discharge or the like.
The advent of the exploding bridge wire provided a method of introducing a large amount of energy into a detonator. Presently available exploding bridge wire detonators usually contain lead azide or pentaerythritol tetranitrate (PETN) as the explosive material. The use of PETN, however, has limited the use of such detonators to relatively low temperature environments. Some detonators have used cyclotrimethylene trinitramine (RDX) or hexanitrostilbene (HNS) as the explosive material. The detonators have still required the introduction of a relatively large electrical charge into the bridgewire to heat the wire to a temperature at which it will explode.
Recently, a device referred to as a semiconductor bridge has been developed for ignition of pyrotechnics and explosives. The semiconductor bridge consists of an "H" shaped, doped silicon material sandwiched between a substrate and an aluminum land. The bridge area provides electrical connection between the lands and the electrical circuit is schematically illustrated in FIG. 1. The semiconductor bridge is actuated by a short, low energy pulse which may be in the range of from about 3 to 5 mJ that vaporizes the bridge material creating a hot plasma that ignites a small quantity of an explosive that is placed in intimate contact with the bridge. The assembly of the electrical circuit and small quantity of explosive in a metal or plastic shell is referred to as an SCB. SCB's operate at much lower input energies than conventional exploding bridgewire devices. A study of the mechanism of SCB's was conducted by Sandia National Laboratories and reported in 1989 in report number SAND 89-2033. The model study was directed to the initiation of the granular explosive 2-(5-cyanotetrazolato)pentaaminecobalt (III) perchlorate (CP).
It would be desirable to produce a detonator having increased temperature stability, shock resistance, and electrostatic discharge resistance.